YellowIbis.com: The best science t-shirts, chemistry t-shirts, nerd t-shirts, and more. 

Size	S	M	L	XL	XXL	3X
Measure A (inch)	28.0	28.5	30.0	31.0	32.0	33.5
Measure B (inch)	18.0	20.0	21.5	24.0	25.5	28.0

This snug-fitting lightweight cotton jersey t-shirt for men has a stylish contoured fit and is ideal for those with a smaller frame. Reinforced shoulder construction maintains shape after repeated washings. Durable double-stitched bottom hem and stretchable cotton collar for lasting comfort and durability. Made from 100% fine combed cotton jersey (except for color code heather gray: 90% cotton, 10% polyester), with a fabric weight of 4.3 oz.

Flex print (plot print with a smooth finish)

• a slightly shiny surface and smooth to the touch
• extremely durable
• up to 3 different colors per design